全文获取类型
收费全文 | 40623篇 |
免费 | 2853篇 |
国内免费 | 242篇 |
专业分类
耳鼻咽喉 | 539篇 |
儿科学 | 899篇 |
妇产科学 | 891篇 |
基础医学 | 5180篇 |
口腔科学 | 938篇 |
临床医学 | 4018篇 |
内科学 | 8090篇 |
皮肤病学 | 766篇 |
神经病学 | 3388篇 |
特种医学 | 1797篇 |
外国民族医学 | 3篇 |
外科学 | 6050篇 |
综合类 | 1013篇 |
现状与发展 | 1篇 |
一般理论 | 30篇 |
预防医学 | 2662篇 |
眼科学 | 1189篇 |
药学 | 3131篇 |
中国医学 | 184篇 |
肿瘤学 | 2949篇 |
出版年
2023年 | 245篇 |
2022年 | 465篇 |
2021年 | 1092篇 |
2020年 | 653篇 |
2019年 | 896篇 |
2018年 | 1122篇 |
2017年 | 806篇 |
2016年 | 953篇 |
2015年 | 1226篇 |
2014年 | 1588篇 |
2013年 | 1943篇 |
2012年 | 3053篇 |
2011年 | 3066篇 |
2010年 | 1727篇 |
2009年 | 1506篇 |
2008年 | 2516篇 |
2007年 | 2688篇 |
2006年 | 2425篇 |
2005年 | 2385篇 |
2004年 | 2215篇 |
2003年 | 1886篇 |
2002年 | 1753篇 |
2001年 | 718篇 |
2000年 | 659篇 |
1999年 | 608篇 |
1998年 | 399篇 |
1997年 | 343篇 |
1996年 | 258篇 |
1995年 | 236篇 |
1994年 | 226篇 |
1993年 | 208篇 |
1992年 | 297篇 |
1991年 | 292篇 |
1990年 | 249篇 |
1989年 | 226篇 |
1988年 | 201篇 |
1987年 | 229篇 |
1986年 | 195篇 |
1985年 | 166篇 |
1984年 | 160篇 |
1983年 | 164篇 |
1982年 | 131篇 |
1981年 | 125篇 |
1980年 | 114篇 |
1979年 | 128篇 |
1978年 | 100篇 |
1977年 | 96篇 |
1976年 | 94篇 |
1975年 | 102篇 |
1974年 | 92篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
3.
Andy KH Lim 《World journal of gastroenterology : WJG》2020,26(10):1020-1028
Rhabdomyolysis is a syndrome of skeletal muscle injury with release of cellular constituents such as potassium,phosphate,urate and intracellular proteins such as myoglobin into the circulation,which may cause complications including acute kidney injury,electrolyte disturbance and cardiac instability.Abnormal liver function tests are frequently observed in cases of severe rhabdomyolysis.Typically,there is an increase in serum aminotransferases,namely aspartate aminotransferase and alanine aminotransferase.This raises the question of liver injury and often triggers a pathway of investigation which may lead to a liver biopsy.However,muscle can also be a source of the increased aminotransferase activity.This review discusses the dilemma of finding abnormal liver function tests in the setting of muscle injury and the potential implications of such an association.It delves into some of the clinical and experimental evidence for correlating muscle injury to raised aminotransferases,and discusses pathophysiological mechanisms such as oxidative stress which may cause actual liver injury.Serum aminotransferases lack tissue specificity to allow clinicians to distinguish primary liver injury from muscle injury.This review also explores potential approaches to improve the accuracy of our diagnostic tools,so that excessive or unnecessary liver investigations can be avoided. 相似文献
4.
5.
Xin Yi Wong Andrew Qi Jun Lim Qianyu Shen John Whay Kuang Chia Min Hoe Chew Wah Siew Tan 《Current medical research and opinion》2020,36(10):1677-1686
Abstract
Objective
Ras wild-type metastatic colorectal cancers (mCRC) may be treated with anti-vascular endothelial growth factor (VEGF) or anti-epidermal growth factor receptor (EGFR) agents. We aim to estimate patients’ preferences for mCRC treatment and relative importance of cost, efficacy improvement, avoidance of side effects and therapy convenience, and relative uptake between profiles that resemble Bevacizumab (anti-VEGF) and Cetuximab (anti-EGFR), two commonly prescribed mCRC targeted therapies. 相似文献6.
7.
8.
9.
Devagi Kanakaraju Nurfatyha Rusydah bt Mohamad Shahdad Ying-Chin Lim Andrea Pace 《Sustainable Chemistry and Pharmacy》2019
The use of multifunctional materials for water remediation is a modern approach where adsorption phenomena and heterogeneous photocatalysis can be applied for the removal of pollutants. Since the ideal remediation system should be able to remove both organic and inorganic pollutants, a crucial aspect to consider is the knowledge of operational parameters affecting the removal process, especially when heavy metal ions are present in concoction as in real systems. Given the proven efficiency of multifunctional TiO2/Alg/FeNPs magnetic beads for the removal of model organic pollutants, this study investigated the possibility to exploit such system also for the removal of mixed heavy metals (MHM), specifically Cr(III), Cu(II), and Pb(II) ions, under ultraviolet irradiation at a wavelength of 254 nm. After a preliminary screening on the optimal catalyst loading, operating parameters such as the initial concentration of metal ions, contact and irradiation time, and pH were investigated to optimize the removal of metal ions using response surface methodology (RSM) via Box–Behnken design. Starting from a MHM solution containing 44 ppm of each metal ion, the removal of Pb(II), Cr(III), and Cu(II) ions in the aqueous solution was nearly completed (>98.4%) for all three ions within 72 min of irradiation at almost neutral pH (pH = 6.8). The stability of TiO2/Alg/FeNPs was confirmed by retrieving and reusing the beads in three consecutive cycles of heavy metals removal without observing significant changes in catalyst efficiency. 相似文献
10.
Keith P. Reber John D. Sivey Matthew Vollmuth Priyansh D. Gujarati 《Journal of labelled compounds & radiopharmaceuticals》2022,65(9):254-263
Parabens are antimicrobial additives found in a wide array of consumer products. However, the halogenated compounds formed from parabens during wastewater disinfection are a potential environmental concern. In order to identify these transformation products and investigate their mechanism of formation, a synthetic route to ethyl parabens labeled with the stable isotope carbon-13 at specific positions within the benzene ring was developed. This efficient two-step procedure starts from commercially available 13C-labeled phenols and involves (1) initial acylation of the phenol via a Houben–Hoesch reaction with trichloroacetonitrile followed by (2) a modified haloform reaction of the resulting trichloromethyl ketone to afford the corresponding 13C-labeled ethyl parabens in 65%–80% overall yield. The scope of the modified haloform reaction was also investigated, allowing for the synthesis of other parabens derived from primary or secondary alcohols, including 13C- and deuterium-labeled esters. In addition, 4-hydroxybenzoic acid can be formed directly from the common trichloromethyl ketone intermediate upon treatment with lithium hydroxide. This protocol complements existing methods for preparing 13C-labeled paraben derivatives and offers the specific advantages of exhibiting complete regioselectivity in the Houben–Hoesch reaction (to form the para-disubstituted product) and avoiding the need for protecting groups in the modified haloform reaction that forms the paraben esters. 相似文献